Monkeypox is caused by the monkeypox virus (orthopoxvirus simiae), which belongs to the genus of orthopox viruses (smallpox viruses).
Monkeypox viruses can be transmitted through handling of infected animals (squirrels, primates and rodents), particularly through contact with blood or infectious body fluids, for example, through a bite. Infected meat can also be the cause. Transmission from person to person is also possible, but the probability of infection is low. Both sexes and all age groups are equally vulnerable. Although young people under age 16 were particularly susceptible during recent outbreaks in the Congo, this is probably due to a lack of vaccination for smallpox or to increased contact with infected animals.
The incubation period is 7 to 21 days. Usually the first symptoms appear after approximately 10 to 14 days. The symptoms are similar to those of human pox. In the early (pre-eruptive) stage, sudden fever, headache, back pain, cough, feeling unwell, severe exhaustion and sometimes diarrhoea set in. Typically, the lymph nodes swell. In the eruptive stage, the typical enanthem (rash) appears on the face, hands and forearms, then commonly spreads. Redness, blisters, pustules and crusts form within a few days in 80 per cent of patients, and 20 per cent suffer a skin rash that can vary in appearance (polymorphous exanthem). Fever is also typical, which usually drops temporarily, but then rises again. Ulcers on the mucous membranes or in the oral cavity also occur more frequently in non-vaccinated patients. Pharyngitis, tonsillitis, conjunctivitis, eyelid edema and lesions in the genital area may also accompany the disease. In rare cases, blindness and disfiguring scars can occur. Fatal forms are seldom.
Since a droplet infection can also cause the disease, medical staff who treat monkeypox patients should take increased precautions, such as wearing gloves, in accordance with DIN EN 420 (protective gloves) and DIN EN 374 (part 1). They should also wear other protective gear such as face masks, protective glasses, coveralls, shoe covers and goggles. Germany’s Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (KRINKO), recommends that a patient with monkeypox should be treated in a room that has at least an isolation-room standard, but an isolation room with antechamber is preferred.
Medical staff should be particularly aware that scabs or crusts remain infectious, even if they have fallen off the skin. The KRINKO recommendations warn that transmission is also possible via clothing and bed linen, so protective measures for contact (gloves, hand hygiene, protective clothing) must be strictly observed. The standard smallpox vaccination is also effective against monkeypox, which is why staff should be vaccinated against smallpox.
The required spectrum of activity for monkeypox is: limited virucidal